The Influence of Age on Clinical Biochemical Parameters in Pure-bred Arabian Mares

Specific reference intervals are needed for each animal species for the appropriate interpretation of the results obtained from serum biochemical tests. The aim of this study was to investigate the blood composition of pure-bred Arabian mares to evaluate the need for defining reference values for different age groups. In all, 90 clinically healthy mares from five farms were used in the trial. For the determination of the effect of age, 90 mares were assigned to six groups. Groups A, B, C, D, E, and F comprised 15 foals aged ≤5 months (mean ± SD: 2.45 ± 1.88), 15 foals aged 6 to 18 months (mean ± SD: 9.33 ± 2.93), 15 mares aged 2 to 5 years (mean ± SD: 3.91 ± 0.7), 15 mares aged 6 to 12 years (mean ± SD: 8.66 ± 2.3), 15 mares aged 14 to 20 years (mean ± SD: 17.81 ± 2.13), and 15 mares aged >20 years (mean ± SD: 22.8 ± 1.93), respectively. Glucose, blood urea nitrogen (BUN), albumin, creatinine, total bilirubin, direct bilirubin, total protein, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), calcium, iron, magnesium, and phosphorus concentrations were measured in the blood serum samples. There were significant age-related alterations for most of the biochemical parameters, except for ALT, LDH activities, and glucose, albumin, magnesium, and iron levels. The results of the present study showed that direct bilirubin (P < .01), ALP, and phosphorus decreased significantly (P < .001), whereas BUN, calcium (P < .01), creatinine, total protein, and total bilirubin increased (P < .001) with age. In foals, ALP activity, direct bilirubin, and phosphorus levels were higher, whereas BUN, creatinine, total protein, total bilirubin, and calcium levels were lower as compared with older animals. Biochemical values determined in the present study serve as reference ranges for pure-bred Arabian mares and can be used for health control and diagnosis of diseases.